The present invention relates more precisely to protective caps for motor vehicle headlamps, which caps are intended to be mounted on the back of a reflector incorporated in the headlamp. Such a cap comprises a sleeve having inwardly projecting means for engaging a rim on the headlamp, and also having a flexible peripheral sealing lip which rests, in use, on the reflector. The above-mentioned projector rim is preferably formed on a bulb-carrier which is fixed to the reflector, but in a variant it may be formed, for example, by fins projecting outwardly from the base of the bulb, as is the case for H4 type bulbs.
Protective caps of the above-mentioned type comprising a sleeve fitted both with fastening means and with a flexible lip are described, in particular, in French published patent application Nos. 2 053 608, 2 056 516, 2 071 808, and 2 436 334, and reference can usefully be made to these prior specifications in order to fully understand the present invention.
Generally speaking, these caps are formed by means of a single-piece hood made of synthetic rubber which is fixed by means of the above-mentioned fastening means against the end of the optical block of a motor vehicle headlamp in order to cover that portion of the reflector on which the bulb is mounted, with the free peripheral edge of the hood being applied, to this end, against the rear surface of the reflector.
Such caps serve firstly to provide a general protective function, and secondly, and above all, to provide water-tightness, i.e. to stop rainwater from running along the reflector and into the opening in which the bulb is engaged. These caps also have the function of protecting the electrical connections which supply electricity to said bulb, and also of protecting the inside of the reflector.
The Applicant has observed, that depending on the function and/or the focal length of the reflectors, the anchor structures (generally a rim on a bulb-carrier) provided on the projector to co-operate with the fastening means disposed on the inside surface of the enveloping protective sleeve of the cap are situated at different distances from the rear surface of the reflector.
As a result, manufacturers have hitherto been constrained to provide a specific model of cap which is compatible with each new application or new type of headlamp.
As a result there are problems of design, problems of providing special manufacturing facilities, and a non-negligible inconvenience in storing a large number of different types of cap.
In order to remedy the above drawbacks, an attempt could naturally be made to use the same model of cap for various types of headlamp. However, the Applicant has observed that given the conventional structure of such caps, such a solution is not entirely satisfactory, in particular when it comes to providing watertightness.
In order to solve these prior difficulties, the applicant has set out to design a universal water tight cap capable of replacing the numerous prior art models.